PLEX-2281: addresses with no contract shouldn't be able to register i… #333

fernandezlautaro · 2026-01-19T06:44:14Z

…n log poller

Jira: https://smartcontract-it.atlassian.net/browse/PLEX-2281

github-actions · 2026-01-19T06:46:08Z

⚠️ API Diff Results - Breaking changes detected

📦 Module: `github-com-smartcontractkit-chainlink-evm`

🔴 Breaking Changes (1)

`pkg/logpoller.Client` (1)

CodeAt — ➕ Added

📄 View full apidiff report

…n log poller

Copilot

Pull request overview

This PR adds contract validation to the log poller's RegisterFilter method to prevent registration of externally owned accounts (EOAs). The validation checks that all addresses in a filter have associated contract code by calling CodeAt on the Ethereum client.

Changes:

Added CodeAt method to the Client interface in the log poller
Implemented validation logic in RegisterFilter to verify addresses are contracts, not EOAs
Updated existing tests to mock CodeAt responses for proper contract validation

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
pkg/logpoller/log_poller.go	Added `CodeAt` to Client interface and implemented contract validation in `RegisterFilter`
pkg/logpoller/log_poller_internal_test.go	Added comprehensive test coverage for contract validation scenarios and updated existing tests with `CodeAt` mocks
pkg/logpoller/log_poller_test.go	Added `CodeAt` mock to fix existing test that now requires contract validation

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Copilot · 2026-01-19T13:00:29Z

pkg/logpoller/log_poller.go

+	for i, addr := range filter.Addresses {
+		code, err := lp.ec.CodeAt(ctx, addr, nil)
+		if err != nil {
+			return pkgerrors.Wrapf(err, "failed to check if address at index %d (%s) is a contract", i, addr.Hex())
+		}
+		if len(code) == 0 {
+			invalidAddresses = append(invalidAddresses, fmt.Sprintf("index %d: %s (EOA, not a contract)", i, addr.Hex()))
+		}


The validation makes sequential RPC calls for each address. Consider batching these CodeAt calls using BatchCallContext to reduce latency when validating multiple addresses in a single filter.

Suggested change

for i, addr := range filter.Addresses {

code, err := lp.ec.CodeAt(ctx, addr, nil)

if err != nil {

return pkgerrors.Wrapf(err, "failed to check if address at index %d (%s) is a contract", i, addr.Hex())

}

if len(code) == 0 {

invalidAddresses = append(invalidAddresses, fmt.Sprintf("index %d: %s (EOA, not a contract)", i, addr.Hex()))

}

// Try to batch the CodeAt calls to reduce RPC latency when validating many addresses.

type batchCaller interface {

BatchCallContext(ctx context.Context, b []rpc.BatchElem) error

}

if bc, ok := lp.ec.(batchCaller); ok && len(filter.Addresses) > 1 {

codes := make([][]byte, len(filter.Addresses))

batch := make([]rpc.BatchElem, len(filter.Addresses))

for i, addr := range filter.Addresses {

// eth_getCode(address, "latest")

batch[i] = rpc.BatchElem{

Method: "eth_getCode",

Args: []interface{}{addr, "latest"},

Result: &codes[i],

}

}

if err := bc.BatchCallContext(ctx, batch); err != nil {

return pkgerrors.Wrap(err, "failed to batch check if addresses are contracts")

}

for i, addr := range filter.Addresses {

if batch[i].Error != nil {

return pkgerrors.Wrapf(batch[i].Error, "failed to check if address at index %d (%s) is a contract", i, addr.Hex())

}

if len(codes[i]) == 0 {

invalidAddresses = append(invalidAddresses, fmt.Sprintf("index %d: %s (EOA, not a contract)", i, addr.Hex()))

}

}

} else {

// Fallback to sequential CodeAt calls if batching is not supported.

for i, addr := range filter.Addresses {

code, err := lp.ec.CodeAt(ctx, addr, nil)

if err != nil {

return pkgerrors.Wrapf(err, "failed to check if address at index %d (%s) is a contract", i, addr.Hex())

}

if len(code) == 0 {

invalidAddresses = append(invalidAddresses, fmt.Sprintf("index %d: %s (EOA, not a contract)", i, addr.Hex()))

}

}

Copilot · 2026-01-19T13:00:29Z

pkg/logpoller/log_poller_internal_test.go

+	contractAddr := common.HexToAddress("0x2ab9a2dc53736b361b72d900cdf9f78f9406fbbb")
+	contractCode := []byte{0x60, 0x80, 0x60, 0x40, 0x52}
+
+	eoaAddr := common.HexToAddress("0x742d35Cc6634C0532925a3b844Bc9e7595f0bEb") // Example EOA address


The comment references 'Example EOA address' but the address is missing a digit. Ethereum addresses should be 40 hex characters (20 bytes), but this address only has 39 characters.

Suggested change

eoaAddr := common.HexToAddress("0x742d35Cc6634C0532925a3b844Bc9e7595f0bEb") // Example EOA address

eoaAddr := common.HexToAddress("0x742d35Cc6634C0532925a3b844Bc9e7595f0bEb0") // Example EOA address

dhaidashenko · 2026-01-19T13:41:24Z

pkg/logpoller/log_poller.go


+	var invalidAddresses []string
+	for i, addr := range filter.Addresses {
+		code, err := lp.ec.CodeAt(ctx, addr, nil)


I wonder what will happen if RPC is down or unavailable. Will workflow DON try to reregister trigger?

If not, maybe we should add some retry logic here

RN probably yes, as we are not discriminating between user and system error.

But this comment made realize once that's fixed on platform side, this coming from the internals calling here lts.EVMService.RegisterLogTracking(ctx, filterQuery) will clearly be swallowed up which defeats the purpose of this early validation.

This being clearly a user error needs to be done differently.

Will update PR to throw a particular error in logPoller and in log trigger check if it needs to be a user error or not.

PLEX-2281: addresses with no contract shouldn't be able to register i…

641847f

…n log poller

fernandezlautaro force-pushed the PLEX-2281_validateAddressOnRegistration branch from 914d244 to 641847f Compare January 19, 2026 06:55

fernandezlautaro marked this pull request as ready for review January 19, 2026 12:59

fernandezlautaro requested a review from a team as a code owner January 19, 2026 12:59

Copilot AI review requested due to automatic review settings January 19, 2026 12:59

product-security-plaid-production bot requested a review from cedric-cordenier January 19, 2026 12:59

Copilot AI reviewed Jan 19, 2026

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fernandezlautaro mentioned this pull request Jan 19, 2026

Plex 2281 validate address on registration smartcontractkit/chainlink#20836

Open

dhaidashenko previously approved these changes Jan 19, 2026

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dhaidashenko reviewed Jan 19, 2026

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dhaidashenko self-requested a review January 19, 2026 13:41

trying user vs system error

b62f0bb

fernandezlautaro dismissed dhaidashenko’s stale review via b62f0bb January 19, 2026 16:50

fernandezlautaro requested review from a team as code owners January 19, 2026 16:50

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PLEX-2281: addresses with no contract shouldn't be able to register i… #333

PLEX-2281: addresses with no contract shouldn't be able to register i… #333

fernandezlautaro commented Jan 19, 2026 •

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-	for i, addr := range filter.Addresses {
-		code, err := lp.ec.CodeAt(ctx, addr, nil)
-		if err != nil {
-			return pkgerrors.Wrapf(err, "failed to check if address at index %d (%s) is a contract", i, addr.Hex())
-		}
-		if len(code) == 0 {
-			invalidAddresses = append(invalidAddresses, fmt.Sprintf("index %d: %s (EOA, not a contract)", i, addr.Hex()))
-		}
+	// Try to batch the CodeAt calls to reduce RPC latency when validating many addresses.
+	type batchCaller interface {
+		BatchCallContext(ctx context.Context, b []rpc.BatchElem) error
+	}
+	if bc, ok := lp.ec.(batchCaller); ok && len(filter.Addresses) > 1 {
+		codes := make([][]byte, len(filter.Addresses))
+		batch := make([]rpc.BatchElem, len(filter.Addresses))
+		for i, addr := range filter.Addresses {
+			// eth_getCode(address, "latest")
+			batch[i] = rpc.BatchElem{
+				Method: "eth_getCode",
+				Args:   []interface{}{addr, "latest"},
+				Result: &codes[i],
+			}
+		}
+		if err := bc.BatchCallContext(ctx, batch); err != nil {
+			return pkgerrors.Wrap(err, "failed to batch check if addresses are contracts")
+		}
+		for i, addr := range filter.Addresses {
+			if batch[i].Error != nil {
+				return pkgerrors.Wrapf(batch[i].Error, "failed to check if address at index %d (%s) is a contract", i, addr.Hex())
+			}
+			if len(codes[i]) == 0 {
+				invalidAddresses = append(invalidAddresses, fmt.Sprintf("index %d: %s (EOA, not a contract)", i, addr.Hex()))
+			}
+		}
+	} else {
+		// Fallback to sequential CodeAt calls if batching is not supported.
+		for i, addr := range filter.Addresses {
+			code, err := lp.ec.CodeAt(ctx, addr, nil)
+			if err != nil {
+				return pkgerrors.Wrapf(err, "failed to check if address at index %d (%s) is a contract", i, addr.Hex())
+			}
+			if len(code) == 0 {
+				invalidAddresses = append(invalidAddresses, fmt.Sprintf("index %d: %s (EOA, not a contract)", i, addr.Hex()))
+			}
+		}

	eoaAddr := common.HexToAddress("0x742d35Cc6634C0532925a3b844Bc9e7595f0bEb") // Example EOA address
	eoaAddr := common.HexToAddress("0x742d35Cc6634C0532925a3b844Bc9e7595f0bEb0") // Example EOA address

PLEX-2281: addresses with no contract shouldn't be able to register i… #333

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⚠️ API Diff Results - Breaking changes detected

📦 Module: github-com-smartcontractkit-chainlink-evm

🔴 Breaking Changes (1)

pkg/logpoller.Client (1)

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Pull request overview

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fernandezlautaro commented Jan 19, 2026 •

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📦 Module: `github-com-smartcontractkit-chainlink-evm`

`pkg/logpoller.Client` (1)